Lesser Swallow Prominent Notodontidae

Pheosia gnoma (Fabricius, 1777)

Description: Wingspan 46-58mm. Adults at rest appear whitish-brown. The forewings are ochreous-white with a dark brown, elongated apical patch along the costa. There is also a fine white line and a wedge-shaped, white mark along the marginal edge, and a sub-dorsal streak from the basal area to the outer margin of the wing. The hindwing is similar in colour with a small dark discal spot. The thorax and abdomen are dark brown.

Similar Species: Swallow Prominent P. tremula but this lacks the white, wedge-shaped streak on the forewing.

Key Identification Features:

Sets:  male upperside

Flight Period: Late April until the end of August; sometimes a little later in upland localities.

Status: Common and widespread in the southern counties; apparently more local in northern counties.

Ecology: Found in a variety of habitats particularly bogs, fens, damp woodland and, occasionally, urban areas. Adults come frequently to light in small numbers. The larvae are more elusive than the adults and have only been seen on a few occasions. Late July until the end of August is perhaps the best time to find them. In N. Ireland it has been recorded feeding on birch Betula spp. It overwinters as a pupa.

World Distribution: Throughout Europe as far east as Siberia.

Bradley & Fletcher number: 2006 Agassiz number: 71.018

Additional information:

UK Moths account


 Thompson, R. S. & Nelson, B., 2003 (Oct 2). [In] The Butterflies and Moths of Northern Ireland